1. Field of the Invention
An aspect of the present invention relates to an image forming apparatus, and, more particularly, to an image forming apparatus including a plurality of photosensitive bodies, scanning units, and a photosensitive body fixing apparatus, in which the photosensitive body fixing apparatus allows assembly tolerances such as the parallel alignment between the photosensitive bodies and the scanning units to be easily adjusted and high image quality may be obtained.
2. Description of the Related Art
An electrophotographic image forming apparatus produces a monochrome image or a color image by forming an electrostatic latent image on a photosensitive body charged to a uniform electrostatic potential by scanning a laser on the photosensitive body, developing the latent image by supplying toner of a predetermined color to the photosensitive body, and transferring and fusing the image to a sheet of paper.
In general, an electrophotographic color image forming apparatus includes one or more scanning units that scan light onto a photosensitive body on which an electrostatic latent image is to be formed, a plurality of developing units that contain toner of different colors, a transferring unit that transfers a developed toner image to a sheet of paper, and a feeding unit that contains and feeds sheets of paper.
Each of the developing units for each color is installed at a predetermined position along a guide surface formed on a main body frame of the image forming apparatus. Each of the scanning units is either assembled into the main body frame or assembled into an individual frame and then integrally installed in the main body frame while being kept parallel to a plurality of photosensitive bodies. The positions of the respective photosensitive bodies may be selected as reference points in assembling the plurality of developing units and scanning units.
When the units are installed in the main body frame, the positions of the developing units, the scanning units and the photosensitive bodies between the scanning units and the developing units must be strictly controlled so as to provide for accurate color overlapping, uniform color representation, and to avoid color banding.
Meanwhile, if each of a plurality of photosensitive bodies is fixed individually to the main body frame, managing assembly tolerances such as the distance between the photosensitive bodies, the parallel alignment between the scanning units and the photosensitive bodies, and the focal length of the light may be difficult. Further, when each of the plurality of photosensitive bodies is removed individually from the main body frame for maintenance, the photosensitive body must be installed at/separated from a predetermined position regardless of the proficiency of an operator or the presence of an assembly jig.